An F15 has to fly to and from a base. In any realistic war senario Pakistan willIn a conventional war if your ground forces mass USAF bombers will destroy you. A Single F-15 can destroy multiple tanks or artillery guns. Pakistani army can withdraw to densely populated cities. it would depend on how the Pakistani populace wants to resist.
1) Pre war tell every nearby nation who might think of hosting the US Force to; not do that since we will then attack said host nation directly
2) Target bases, logistic dumps communication nodes.
Basically if we fight the war on the enemy's terms, we will lose. We are not going to fight it their way.